Mechanism to maintain constant the required length of an endless driving means



1937. F. A. NICHOLSON ET AL 2,099,220

' MECHANISM 1'0 MAINTAIN CONSTANT THE REQUIRED LENGTH OF AN ENDLESSDRIVING MEANS Filed Dec. 21, 1956 2 Sheets-Sheet 1 ATTORNEY Nov. 16,1937. F. A. NICHOLSONET AL MECHANISM TO MAINTAIN CONSTANT THE REQUIREDLENGTH OF AN ENDLESS DRIVING MEANS '2 Sheets-Sheet 2 Filed De c. 21,1956 1 I n l Fly. 6

' INVENT RS W11. M01 7: 1?! Tel-MRO F/PEO c/r A. NICHOLSON ATTQRNEYPatented Nov. 16 1937 UNITED STATES,

PATENT. OFFICE MECHANISM. TO MAINTAIN CONSTANT, TH]? REQUIRED LENGTH OFAN'ENDLESS DRIV- ING MEANS Frederick A. Nicholson and Wilmot T.Pritchard,

Seattle, Wash, assignors to Stetson-RossMachine Company,S'eattle,.Wash.,. a corporation of" Washington- Application. December21, 1936, Serial No. 116;:162

v 6 Claims.

supports, it has beenlthe-practice to use tightener means to maintainthe proper tension onthe maintain the desired tensionof the endlessdriV- ing-means. Such prior art'devices were not satisfactory as theydid not provide the desired degree 35 f simplicity to prevent costlyshut-downs and continual repair of the mechanism. Also whereheavydrivingstrains-were encountered, thedifilculties wereincreasedi' It is theobject of our inventionto' providea 40; simple, efiicient andpracticalmechanism' which will permit an endless driving= means tobethreaded over a plurality of wheels, some-of which aremountedonfmova'ble supports; and where'the lngthnf the endless driving?means requiredwill remain" substantially constant despite the move--ment of some of the' wheel bearing means and wheelmeansthereon;

It is a further object of this invention to providea wheel end'lessdriving mechanism which in-- 50 cludesa wheelwhi'ch is subject tocontinual'movement 1 during operation;

It is a further object of thisinvention' to provi'de in such mech'anisma driving connection with awhee-l whichis substantially floatinglymounted '55: -relatively-tb thedriving means. l

" some of Y which wheelswere mounted on movable 1 It is moreparticularly an object of this invention to provide i n such a-mechanismtwo spaced apart wheels,- a third movably mounted wheel positionedsubstantially intermediate of andibffset relatively to said two-wheels,and an endless driving. means threaded over all. of said wheels to theend of requiring a substantially constant 1 length of endless drivingmean's, despite the movement required-of said third wheel.

It is more particularlyan object of. this invention to provide in suchmechanism, means which will provide substantially uniform tension ofthe:

endless driving means" where a wheel moves'within the requirementsnecessary to drive the resiliently mounted feeding means of: a planingdevice 1 The above: mentioned; general objects of our invention,together with others iinherent in the same, areattainedby the mechanismillustrated in the following drawings, the. same being preferredexemplaryforms-of embodiment of. our

invention, throughout which drawings like ref-' erence numerals indicatelike parts:

Figurelis a view in elevation,.with parts-removed, of a planer mechanismembodying this invention;

Fig. 2 is a detached fragmentary view in elevattion of theportion-of'the driving mechanism.

embodied in this invention, showing by dot and dash lines a positionwhich the movably mounted wheel'may'assumaand also showing by dotanddash lines the; elliptical path which the center of such movably mountedwheel would tend to follow;

Fig. 3 is a schematic view'illustrating a position of 'the upperfeedlbed and positions which the lower feed bed may assume;

Fig. 4 is a detached elevatiomwith parts broken away, showing the upperand lower'endless feed beds and theresilient supporting means for thelower feed bed;

Fig. 5 is aview'of a modified form of the invention similar to Fig. 4,except showing a pair of upper feed rolls and a pair of lower rollsinstead of feed beds; and

Fig. 6 is a View of astill further modified form of the inventionsimilar to Fig. 5, except showing the invention in connection with oneupper feed roll and one lower feed roll.

In describing and illustrating this invention, We have shown the same asapplicable in connection withthe driving-of endless feed beds and feedrolls of a planing device. It is to be expressly understood that thisinvention is not limited toany-such specific application and the same isset forth only as illustrative of one environment in which thisinvention may be utilized. Also for purposes of definiteness ofillustration,

we have illustrated the invention in connection with an endless sprocketchain threaded over a plurality of sprockets. In this connection themechanism may obviously be used in connection with any wheel means andendless driving means threaded thereover, and sprockets and an endlesssprocket chain are only examples thereof. 7

In Figure 1 all of the details of the planer mechanism are not shown andwill be only generally described, as such details are not consideredessential to this invention.

A frame in supports the planer mechanism. The in feeding mechanism,generally indicated by H in Figure 1, illustrates the invention of thisapplication and Will be particularly discussed after a general referenceto the other portions of Figure 1. This feeding mechanism urges lumberstock past a lower cutter head mechanism l2 and an upper cutter headmechanism IS. The lumher is then urged past edge matcher mechanismindicated generally by l4. Lower and upper face pattern forming cutterhead mechanisms l5 and I6 may be provided in connection with the planermechanism.

The out feeding mechanism, generally indicated by H, and shown at theright of Figure 1 30 of the drawings, is the subject matter of ourcopending application Serial No. 116,960. This out feeding mechanismserves to drive feed rolls to remove the finished lumber from themachine. 'Referring to Fig.4 of the drawings: The upper feed bedcomprises sprockets I8 and 49. Endless feed bed conveyor chain 20 isthreaded over sprockets l8. and I9. Shafts 2| and 22 are mounted on theframe 23 of the upper feed bed. These shafts 2! and 22 are, also mountedon movably mounted frame member 24, as is more particularly discussed inour copending application Serial No. 116,961, wherein such invention isclaimed. I

The lower feed, bed comprises sprockets similar to sprockets l8 and 19mounted on shafts. 25 and 26. These shafts 25 and 26 are mounted on theframe 21 of the lower feed bed, butsuch shafts are independently mountedon the movably mounted frame 24. An endless conveyor chain 28 isthreaded over the sprockets in the lower feed bed supported from shafts25 and 26. The upper feed bed or the lower feed bed may be provided withadjusting means to provide the proper tension of the endless feed bedconveyor chains 20 and 28. This may be accomplished by providing anywell known adjusting mechanism, such as illustrated in connection withthe shaft 25.

The lower feed bed, see Fig. 4, is mounted for resilient adjustablesupport, which supporting structure is the subject matter of ourco-pending application Serial No. 116,963. This is accomplished bypivotally securing the upper portion of frame 21 to the link 29. Thislink 29 is pivotally secured by pivot means 39 to the main frame 19 ofthe machine. The lower portion of the frame 21 is secured by pivot means3| to horizontal link 32. 32. A spring 34 is slidably positioned onhorizontal link 32 between the nut means 33 and a pivot block 35. Thispivot block 35 is slidably positioned on link 32 and is secured by apivot means 36 to the main frame ID of the machine. Another spring 31,similar to spring 34, is slidably positioned on horizontal link 32between said pivot b1ock35 and the nut means 38, which is Nut means 33is threadedly secured on link threadedly connected with said link 32.The springs 34 and 31 are compressed by the nut means 33 and 38 so thatthe lower feed bed tends to assume a horizontal position when pivotallysupported from link 29.

.Another link means 39 is pivotally secured to the frame 21 and mayconnect with the pivot means 3|. This link means 39 is provided with nutmeans 49 threadedly secured .to the link means 39. A spring 4! isslidably positioned on the link 39'between said nut means 49 and acollar 42 which is slidingly positioned on said link means 39 Nutmeans43 secures collar 42 in place. Collar 42, and in turn the lower feedbed, may be adjustably positioned by any suitable means, such as by bellcrank 44 having one arm thereof pivotally secured to the collar 42 bypivot means 45. The bell crank 44 is secured by pivot means 46 to themain frame [0 of the machine. The other arm of the bell crank 44 ispivotally connected with a link 41 which is in turn pivotally connectedwith a screw 48. a A worm wheel 49 is threadedly connected with'screw43. The worm wheel 49 is held in place between projecting portions ofthe main frame I 9. A worm 56 engages with worm wheel 49. Through themechanism described the lower bed may be raised or lowered and thesprings 4!, 34 and 31 supporting the lower bed will providesubstantially the same degree of tension for the lower feed bed in anyadjusted position thereof. 7

The means for adjusting the movably mounted frame 24 is not illustratedin this application as the same constitutes no part of theinventionhereof, but the same is fully illustrated and described in ourco-pending application Serial No. 116,961.

Referring to Fig. 2; The shaft 2|, upon which is mounted sprocket I8 ofthe upper feed bed, is journaled in the .movable plate 24 and hassprocket wheel 51 mounted thereon. The shaft 26, upon which is mounted asprocket of the lower feed bed, passes through the movable plate 24 andis not connected therewith. On this shaft 26 is mounted a sprocket wheel58. A stub shaft,

59 is mounted on the movable plate 24 and a sprocket wheel 60 is mountedon said stub shaft 59.

A plate 6|, see Fig. 1, is pivotally secured on pivot 62 to the movablymounted frame 24. Adjusting screws 63 threaded through lugs 64 permitangular adjusting movement of plate Bl relative to the movably mountedframe 24. A stub shaft 65 is mounted on the plate 6L. For purpose of'clearness of illustration the stub shaft 65 and sprocket wheel 66 areshown in Fig. 2 of the drawings without the plate 6i and adjusting meanstherefor. This adjusting means is provided for initial adjustment of theendless driving chain 1|. Sprocket wheels 6'! and 68 are mounted onshafts 69 and 19 which are secured to the main frame [0 of the machine.

Thus, sprocket wheels 51, 66 and 60 are moved upwardly with theadjustable frame '24 and the sprockets 61, 68 and 58, being independentof device will operate under such conditions.

tion. will obtain. for theimovement of shaft 86 and As the frame 21: ofthe lower feed bed is resiliently supported by springs 34, 31 and 41,the

sprocket wheel 58 supported from the shaft 26,.

willtend to move in substantially a vertical path. At the same time theendless chain 1|,which-is threaded over the sprocket wheels 61, 68, 68,51' and 68, will tend to assume the elliptical path numbered 58 in Fig.2 and shown by dot and dash lines. 'Through the central portion of thesaid elliptical path, in which the center of the shaft mounting sprocketwheel 58 moves, as required in a planing machine, there is substantiallyno difference between the substantially vertical plane in which thesprocket wheel 58 is actually moved, and theelliptical path wherein theone lap of chain between sprocket wheel 58 and sprocket wheel 86 exactlycompensates for the difference in length of the lap of chain between thesprocket wheel 68 and 68. Although the path of the sprocket wheel 58 issomewhat complex (see Fig. 3), due to the fact of thepivotal supportfrom the link or arm 28 on the pivot 38, and the resilient side supportoffered by springs 34 and 31, and the lower support offered by springAl,still we have found in practical operation that the path of the sprocketwheel 58 supported on the shaft 26 is substantially a vertical. planeand will permit compensation as is indicated particularly in Fig. 2 ofthe drawings.

In Fig. 5 of the drawings two upper feed rolls 12 and I3 are illustratedand lower feed rolls I4 and i5 are also illustrated. If such feed rollsare used they will replace the endless feeding mechanism most clearlyillustrated in Fi 4 of the drawings. Upper feed rolls I2 and 13 areconnected by wheels 16' and endless driving means 11. The lower feedrolls I4 and 15 are mounted on shafts 86 and 867 and are connectedtogether by wheels l8 and endless driving means 19., The upper feedrolls I2 and I3 are mounted onshafts 88 and SI respectively. On theseshafts 88 and 8i, respectively, are also mounted sprocket wheels 82 and83. The supporting frame 84 for the upper feed rolls supports the shafts88 and 8| and said frame is connected with a movable frame, such as themovably mounted frame 24 heretofore discussed. The supporting frame, 85for the lower feed rolls may be supported in a manner identical with thesupport for the frame 2'! of the lower feed bed, and in the interest of.brevity similar numbers will be applied to similar parts, and no furtherdescription will be given.

The lower feed roll 15 is mounted on a shaft- 86, which shaft 86 isfixedly connected with av sprocket wheel 81. A driving sprocket wheel 88is connected to a source of power (not shown) and isrotatably supportedon a shaft 89 mounted'on.

mechanism for the conveyor beds, previously described.

I Here the shaft 86 supporting the sprocket wheel 81 moves identicallywith the movement of the sprocket wheel 58 supported on the shaft 26,

the movement of which was discussed particularly in connection with Fig.2. Similar compensasprocket wheel 81.

In Fig. 6 of the drawings, we haveillustrated a an adjustable plate 99.The adjustable plate 88 is mounted'on pivot means I88, which pivot meansisin turn mounted on the mainframe I8 of the machine. The adjustablemeans 99- supports'a stub shaft I-8I which stub'shaft in turnsupportsasprocket wheel I82. A sprocket wheel I-83-is supported on the shaft 81.--By operation the adjustablescrews- I84," the shafts 91 and 'I8I maybeangularly adjusted relative to each other. This adjusting feature ismore particularly de* scribed in our co-pending application Serial; No.116,968 and provides for an initial adjustment, of the endless drivingchain sprocket wheels I82 and I83. As the adjusting means, which is thesubject matter of this invention, may be used either with or withoutsuch adjustable plate 98, the same is not here considered in detail. v

The shaft 98 which supports the lower feed roll 96 is journaled in alink means I86; This link means is pivotally supported by pivot meansI81 from the main frame I8 of. the machine. The other end of the linkmeans I86 is pivotally se-' cured to a link means I8. On this ,linkmeans I88, is fixedly secured a collar I88. A spring means I I8 isslidably mounted on thelink means I85 threaded over' I88and ispositioned between the collar ,I'88 and another collar I'I'I'. Nut meansH2. are provided between lug 'portions'of' the main frame I8. A; wormIIBJmeshes with the worm wheel I'I'I.

Thusthe link means I86 supporting the lower feed roll 86, together withits connected parts, is resiliently supported and may be adjustedwithout changing the resilient support of the spring H8. A sprocketwheel H9 is secured on shaft 98. A shaft I28 secured to the main frame Iof the machine rotatably supports a sprocket wheel I2 I. The endlessdriving chain I85 is threaded about sprocket wheels I82, l83 and I2I.The sprocket wheel I2I' is connected to a source of power (not shown).

Thus the sprocket wheel H8 is supported for substantially verticalmovement between two sprocket wheels I83 and I2 I, and as this sprocketwheel I I8 moves upwardly and downwardly, compensation for movement ofsprocket wheel H9 will take place similarly to the compensation formovement of sprocket wheel 58, particularly described in connection withFig. 2.

In the foregoing we have described the invention as applicable to aplaning device, such as disclosed in our vco-pending application SerialNo. 91,568. In such a planing device the lower bed is resilientlymounted as distinguished from the commercial prior art planing machineswhere the upper beds are resiliently mounted. Obviouslythe inventionherein can be readily adapted to ordinary planing machines, as well asto the planing mechanismidisclosed in said application Serial No.91,568. i j I Obviously, changes may be made in the forms, dimensionsand arrangement of the parts of our invention, without departing fromthe principle thereof, the above setting forth only preferred forms ofembodiment. i

' We claim:

1'.In a device of the class described, two spaced apart wheels; fixedlymounted bearing means supporting each of said two wheels for rotarymovement; a third wheel positioned substantially intermediate of and oifset relatively to said two wheels; movably mounted bearing meanssupporting said third wheel for rotary movement and for movementsubstantially in a plane approximately parallel to a plane passingbetween said two wheels; and endless driving means threaded over saidtwo wheels and said third wheel, whereby substantial movement of saidthird wheel in said; plane may obtain without requiring a materialchange of length of said endless driving means. i a

. 2. In a device of the class described, two substantially verticallyspaced apart Wheels; fixedly mounted bearing means supporting each ofsaid two wheels for rotary movement; a third wheel positionedsubstantially intermediate of and later ally off set relatively to saidtwo wheels; movably ,mounted'bearing means supporting said third wheelfor movement, substantially in an approximately vertical plane; andendless driving means,

wheel and said driven wheel for rotary movement; another driven wheelpositioned. substantially intermediate of and laterally oil-setrelatively to said driving wheel and said driven wheel; movably mountedbearing means supporting said other driven wheel for rotary movement andfor movement substantially in an approximately vertical plane; andendless driving means threaded over said driving wheel, said drivenwheel and said other driven wheel, whereby substantial vertical movementof said other driven wheel may obtain without requiring a materialchange of length of said endless driving means.

4. In a device of the class described, two spaced apart wheels; fixedlymountedbearing means supporting each of said two wheels for rotarymovement; a third wheel positioned substantially intermediate of andoffset relatively to said two wheels; movably mounted bearing meanssupporting said third wheel for rotary movement and for movementsubstantially in a plane approximately parallel to a planepassingbetween said two wheels; other wheel means offset relatively'to bothsaid .two spaced apart wheels and saidj-third wheel and offset in thesame direction as said third wheel; and endless driving means threadedover one of said two spaced apart wheels; over said thirdwheel, over theother of said two spaced apart wheels, over said other wheel means, andback to the one of said two spaced apart wheels, whereby substantialmovement of said third wheel in said plane may ob- ,erally offsetrelatively to said two wheels; movably mounted bearing means supportingsaid third wheel for movement substantially in an approximately verticalplane; other wheel means laterally offset relativelyto both said twospaced apart wheels and said third wheel and laterally cfiset in thesame direction of said third wheel; and an endless driving meansthreaded over one of said twoispaced apart Wheels, over said thirdWheel, over the other of said two spaced apart wheels, over said otherwheel means and back to the one of said two spaced apart Wheels, where-'byv substantial vertical movementof said third wheel may'obtain withoutrequiring a material change of length of said endless driving means.

6Q In a device of the class described, a driving wheel, and a'drivenwheel positioned in substantially vertically spaced apart relation;fixedly mounted bearing means supporting said driving Wheel and saiddriven wheel for rotary movement;

7 another driven wheel positioned substantially in-,

termediate of and laterally offset relatively to said driving wheel andsaid driven wheel; movably mounted bearing means supporting said otherdriven wheel for rotary movement and for move-

